从 MT2-AM8 模拟量模块迁移到 Easy521 PLC（Modbus TCP）

- 读取 D700（阀后流量）、D710（阀后压力）、D720（阀前压力），
  读用功能码 03，0~32000 线性映射到各自量程（300 SLM / 400 kPa / 300 kPa）
- 输出 D730（电机位置，0~10V），写用功能码 06，行程仍为 0~1000、死区 800
- 复用 MT2 骨架，保留 get_flow/get_pressure/set_motor_position 接口，
  channel 参数改为直接 Modbus 地址
- config.py 新增 PLC 设置，保留 MT2AM8 设置为死代码（MT2AM8Client 类保留）
- 同步更新 README.md 中的硬件接线、配置默认值与模块职责描述

test_valve.py

@@ -173,7 +173,7 @@ def set_opening(hardware, opening_pct):
     position = motor_position_for(opening)
     if not hardware.set_motor_position(
         position,
-        channel=config.MOTOR_OUTPUT_CHANNEL,
+        channel=config.MOTOR_OUTPUT_ADDR,
     ):
         raise RuntimeError("电机位置写入失败")
     return opening, position
@@ -184,11 +184,11 @@ def read_sensors(hardware, quiet=False):
     output = io.StringIO()
     stream = output if quiet else sys.stdout
     with contextlib.redirect_stdout(stream):
-        flow = hardware.get_flow(config.FLOW_INPUT_CHANNEL)
+        flow = hardware.get_flow(config.FLOW_AFTER_ADDR)
         pressure = (
             None
-            if config.PRESSURE_INPUT_CHANNEL is None
-            else hardware.get_pressure(config.PRESSURE_INPUT_CHANNEL)
+            if config.PRESSURE_AFTER_ADDR is None
+            else hardware.get_pressure(config.PRESSURE_AFTER_ADDR)
         )
     return flow, pressure
 
@@ -199,17 +199,22 @@ def main():
         return 1
 
     try:
-        from PcControl import MT2AM8Client
+        from PcControl import Easy521ModbusClient
     except ModuleNotFoundError as exc:
         print(f"无法导入硬件客户端: {exc}")
         return 2
 
-    hardware = MT2AM8Client(
-        host=config.MT2AM8_HOST,
-        port=config.MT2AM8_PORT,
-        slave_id=config.MT2AM8_SLAVE_ID,
-        pressure_range=config.PRESSURE_RANGE_KPA,
-        flow_range=config.FLOW_METER_RANGE_SLM,
+    hardware = Easy521ModbusClient(
+        host=config.PLC_HOST,
+        port=config.PLC_PORT,
+        slave_id=config.PLC_SLAVE_ID,
+        flow_addr=config.FLOW_AFTER_ADDR,
+        flow_range=config.FLOW_AFTER_RANGE_SLM,
+        pressure_before_addr=config.PRESSURE_BEFORE_ADDR,
+        pressure_before_range=config.PRESSURE_BEFORE_RANGE_KPA,
+        pressure_after_addr=config.PRESSURE_AFTER_ADDR,
+        pressure_after_range=config.PRESSURE_AFTER_RANGE_KPA,
+        motor_output_addr=config.MOTOR_OUTPUT_ADDR,
     )
 
     connected = False
@@ -222,7 +227,7 @@ def main():
 
     try:
         print(
-            f"正在连接 MT2-AM8 {config.MT2AM8_HOST}:{config.MT2AM8_PORT} ..."
+            f"正在连接 PLC {config.PLC_HOST}:{config.PLC_PORT} ..."
         )
         connected = bool(hardware.connect())
         if not connected: